1. Field of the Invention
This invention relates to a mixing apparatus, and in particular to a two stage apparatus for continuously mixing liquids to produce a homogeneous emulsion.
While the apparatus was designed specifically to produce emulsions by mixing an aqueous slurry and an organic solvent, it will be appreciated that the apparatus can be used to mix other ingredients. By "liquids" is meant water, organic solvents and slurries. For example, an aqueous slurry and an organic slurry (an organic solvent with a suspended solid) can be mixed using the apparatus of the present invention.
2. Discussion of the Prior Art
In general, existing mixing devices are single stage mixers including a stirrer. Often, such devices are not sufficiently efficient to produce homogeneous emulsions or at least not in a reasonable period of time.
Searches in the patent literature disclose Canadian Patents Nos. 536,106, which issued to J.A. Carver et al on Jan. 22, 1957 and 817,797, which issued to J.F. Gurley, Jr. on July 15, 1969, and U.S. Pat. No. 3,425,669, which issued to P.G. Gaddis on Feb. 4, 1969, which have elements in common with the invention described herein. However, like the conventional mixer described above, the patented devices are single stage mixers relying, for example on somewhat complicated stirrers to effect mixing. Moreover, existing mixers for producing aqueous slurries usually include a large tank for batch processing of slurries, i.e. for preparing one large batch of slurry at a time. The slurry is produced, the tank is emptied and the process is repeated.